Whose job is it?

A single room that has never been right is almost always an airflow problem rather than an equipment one. Adding capacity does not fix it and frequently makes the rest of the house worse.

• Airflow measured at that register and compared with the others turns the argument into a number.
• The usual causes are a branch added later without rebalancing, a crushed or kinked run, a closed damper nobody knows about, or a return far too small.
• Where the room genuinely has a different load — a converted garage, a sun room — the honest answer is sometimes a separate system for that room alone.
• If somebody has quoted a whole new system for one cold bedroom, get a second opinion.

A stain directly below an air handler is nearly always the condensate: a blocked drain line, a full pan, or a float switch that is missing or has failed. Turn the system off at the thermostat before you call, because the coil is making more water every minute it runs.

• This is the commonest cause of interior water damage we attend, by a distance.
• The float switch is inexpensive and its whole job is to prevent exactly this.
• Where the air handler is in an attic, check whether there is a secondary pan and whether it drains anywhere.
• If the stain is beside rather than below the unit, look at the roof above before assuming it is us.

A stain under a bathroom with no heating or cooling equipment above it is plumbing: a waste connection, a shower pan, a supply fitting or grouting that has failed. There is nothing in that ceiling belonging to us.

• Worth checking whether the stain grows after a shower specifically, which narrows it a great deal.
• If there is a bathroom extract fan above it, its duct can drip condensation in winter — that one is genuinely shared, and we will look at it.
• Otherwise, a plumber first. We would only be adding a visit to your bill.

Damp on an outside wall that worsens after rain is water getting in from outside: flashing, pointing, a blocked gutter, a failed sill or a window seal. It is a building fabric problem and it is not ours.

• Rain-driven damp is worse on the weather side of the building and follows the weather. Condensation damp does not.
• If it is worse in cold weather and not obviously linked to rain, it may be condensation — and that one is partly ours.
• Fixing the source comes before anything mechanical. Drying a wall while water is still arriving achieves nothing.

Ice at the roof edge is an ice dam: heat escaping into the roof space melts snow on the roof, the water runs to the cold eaves and freezes there. The repair is insulation, air sealing and roofing.

• There is a real HVAC contribution and we will tell you honestly whether you have it. Ductwork leaking into an attic, or an attic hatch and light fittings that are not sealed, put heat exactly where it causes this.
• What we will not do is take on the repair. Insulation and roofing contractors own that work.
• Roof clearing is a third trade again, and not something to attempt casually.

A breaker that trips on start-up is usually telling you about the equipment rather than the circuit: a failing capacitor, a compressor struggling to start, a seized fan motor or a dead short in the outdoor unit.

• We test the equipment first. That is the cheaper answer and it is usually the right one.
• If the equipment tests correctly, the circuit, the breaker itself or the wiring becomes the question, and that is an electrician’s.
• Do not keep resetting it. A breaker tripping repeatedly is a protective device doing its job, and forcing it back on is how a fault becomes a fire.

A sewage smell indoors is nearly always a trap that has dried out and stopped sealing, or a waste fault. That is plumbing.

• The one exception is ours: the condensate drain on an air conditioning system has a trap, and if the system has not run for a while it can dry out and let drain gases back up the pipe. We can check and refill that in minutes.
• A rarely used shower, floor drain or basement sink does the same thing, and the heating system then distributes it around the building.
• If refilling the condensate trap does not fix it, the source is elsewhere and it is a plumber’s job.

A winter electricity bill that jumps without a weather change, on a heat pump, usually means the electric back-up heat has been running far more than it should. It is silent and it is expensive, which is exactly why it goes unnoticed.

• The usual causes are a thermostat wired or configured wrongly — frequently after a smart thermostat was fitted — a refrigerant charge that is out, or an outdoor unit that cannot breathe.
• An “emergency heat” setting left on will do it on its own.
• On a gas or oil system a jump usually points at combustion efficiency or at something running that should not be.
• If the equipment tests correctly and the settings are right, the question moves to tariff and metering, which is the utility rather than us.

Winter condensation on the inside of glass means the indoor air holds more moisture than the coldest surfaces can tolerate. Both halves of that sentence have owners.

• Ours: whether a humidifier is set too high, whether bathroom and kitchen extract actually works and actually discharges outside, and whether ventilation is adequate for how the building is used.
• The building’s: how cold the glass and frames are, which is glazing and insulation rather than mechanical.
• Sometimes a third party: a wet crawlspace or basement will supply moisture to the whole house all winter, and that is a damp-proofing question.
• We will measure the humidity and the extract, and say which part is ours.

Get everybody out. Do not switch anything on or off, do not use a light switch, and do not use a phone indoors. From outside, call 911 and your gas utility’s emergency line.

• They come out for this, they come quickly, and they do not charge you for being wrong.
• A carbon monoxide alarm sounding is the same instruction: out first, call from outside.
• We are a heating contractor. We are not the right first call for a suspected gas leak and we would rather say so than have you wait for us.
• Once it has been made safe, we can look at the appliance side of it.